Sunday, February 19, 2006

Christmas Books: 2

In an earlier post, I mentioned books I liked enough to buy multiple copies as Christmas gifts and gave one example. Here is another.

Chimpanzee Politics by Frans de Waal is based on a close study, over a period of years, of a chimp colony. The chimps come across as more like dumb people than smart animals. My favorite anecdote:

While the chimps were in their indoor habitat, the experimenters buried some grapefruit in a patch of sand in their outdoor habitat. The chimps saw the experimenters go by with the grapefruit, so knew something was up.

When released outdoors, they made an apparently unsuccessful search for the grapefruit. Then it was naptime. When the rest of the chimps were asleep, one of the low status males got up, went straight to the buried graperfuit, dug them up and ate them. To me, at least, that is striking evidence not only of rational behavior but of rational thought behind the behavior.

The other interesting observation was reflected in the title. The dominant male might or might not be the biggest and strongest—because the political struggle that determined dominance involved an elaborate pattern of shifting alliances.

The rationality of digging up the grapefruit is not so obvious to me. The benefit is that the male gets all the grapefruit for himself, to eat or share with others. If he keeps it all for himself, he runs the risk of the other chimps becoming weak from malnourishment, leaving the entire colony and thus himself more vulnerable to predatory attack. Secondly, there is the risk of being caught digging up the food by his own while he thinks they are asleep. I don't know how they might punish him if this happened, or even if they would punish him at all. Perhaps he would be even rewarded for finding the grapefruit after they could not. Regardless, this behavior is not without its costs.